So the camera i have is a sony rx10-- i find it to be very good for taking clear, crisp shots of my photos-- however i run into issues when uploading my photos to platforms like eBay and especially this website, liveauctioneers.

my question is, what do i need to do with my camera settings to not have my higher res image compressed into their thumbnail? because i find that the image is getting compressed and i am losing picture quality and sharpness.

You may not be able to set your camera to do that specifically, rather do it in software before uploading. Any good quality image editing application (PS, LR, PSP, etc) will do near lossless reductions.

You may not be able to set your camera to do that specifically, rather do it in software before uploading. Any good quality image editing application (PS, LR, PSP, etc) will do near lossless reductions.

Click to expand...

Photoshop then may help, or maybe gimp? i don't want to lose any sharpness-- i feel like i may have a camera that's too good for these selling platforms.. the higher megapixels don't seem to really benefit or be of use all that much...

The file size limitation the web site has will not affect the image quality.
Letting the web site set the image resolution of your photos will.
You need to prepare the photo for web display BEFORE you upload it to the web site.
You change the image resolution after finishing (editing - set white point, black point, mid-tone contrast, noise reduction, sharpen, etc) a Raw file of the image.
You don't want the camera doing any editing by making a JPEG file in the camera.

Sharpness is about way more than the MP of the camera you use.
Your Sony RX10 has a small image sensor being only 13.2 x 8.8 mm in dimensions, has a 3:2 (1.5) aspect ratio, and image resolution of 5472 x 3648 pixels.
In comparison a full frame, 135 format (35 mm) sensor is 36 x 24 mm.
Being a small image sensor makes the pixels small too (pixel pitch) when there are 20 million on them packed into such a small space.Conclusion - Cons

Pricey

JPEG images are over-sharpened and over-processed

Which is why full frame DSLRs usually make better (sharper, less image noise) photographs than point & shoot cameras that have small image sensors.

. . . Part of the problem with trying to explain why the RX10 costs so much (and we're still not sure why it costs quite so much), is that it requires you to understand not just the equivalent focal length range and aperture, but also the effect of sensor size. . .